Must Know ES6 Features for Modern Javascript Development

ES6, also known as ECMAScript 2015, is a major update to the JavaScript language that was released in 2015. It introduces new features and syntax that make it easier to write complex and maintainable code.

Here are some examples of ES6 features:

Arrow functions

Arrow functions are a more concise way to define functions in JavaScript. They are especially useful for writing inline functions and for preserving the value of “this” inside the function.

// ES5 function
var double = function(x) {
  return x * 2;

// ES6 arrow function
const double = (x) => x * 2;

Template literals

Template literals are a new way to define strings in JavaScript that allows for embedding expressions and variables directly in the string.

// ES5 string concatenation
var name = "Alice";
console.log("Hello, " + name + "!");

// ES6 template literal
const name = "Alice";
console.log(`Hello, ${name}!`);

Let and Const

The “let” and “const” keywords are new ways to define variables in JavaScript that have block scope. This means that they are only visible within the block they are defined in.

// ES5 variable
var x = 1;
if (true) {
  var x = 2;
console.log(x); // 2

// ES6 let variable
let y = 1;
if (true) {
  let y = 2;
console.log(y); // 1

// ES6 const variable
const z = 1;
z = 2; // Error: Cannot reassign const variable


ES6 introduces a new syntax for defining classes in JavaScript, making it easier to write object-oriented code.

// ES5 constructor function
function Person(name, age) { = name;
  this.age = age;

Person.prototype.greet = function() {
  console.log("Hello, my name is " +;

// ES6 class
class Person {
  constructor(name, age) { = name;
    this.age = age;

  greet() {
    console.log(`Hello, my name is ${}`);


ES6 introduced a new feature called modules, which simplifies JavaScript code organization and reusability. In this article, we’ll explore what ES6 modules are and how they work.

Before ES6, there was no standard way to organize and reuse code in JavaScript. Developers had to rely on various workarounds, such as global variables, immediately invoked function expressions (IIFEs), and CommonJS modules (which were not part of the language specification).

ES6 modules aim to solve these problems by providing a standard syntax for importing and exporting code between JavaScript files. Here’s an example:

// greet.js
export function greet(name) {
  console.log(`Hello, ${name}!`);

// app.js
import { greet } from './greet.js';


In this example, we have two files: greet.js and app.js. greet.js exports a function called greet, which takes a name parameter and logs a greeting to the console. app.js imports the greet function using the import statement and calls it with the name “Alice”.

ES6 modules support both named exports (like greet in the example above) and default exports (which can be imported with any name). They also support importing from external modules, which can be installed using package managers like npm.

ES6 modules have several advantages over previous methods of organizing and reusing code.

  1. Provide a clean and standardized way to structure code, which makes it easier to reason about and maintain.
  2. Enable better encapsulation and reduce the risk of naming collisions and other erorrs
  3. Facilitate code reuse and sharing, as modules can be imported into any project that uses ES6

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